For example, systems of vehicles such as brakes and suspensions actuate various devices using compressed air. Some of such systems include a compressed air drying system located downstream of the compressor to remove water and oil from compressed air.
An example of a known compressed air drying system includes an air dryer, which includes a desiccant, and an oil separator (for example, see Patent Document 1). The oil separator collects liquid that contains oil and water and is discharged from the air dryer by regenerating the desiccant.